/* * Audio and Video frame extraction * Copyright (c) 2003 Fabrice Bellard * Copyright (c) 2003 Michael Niedermayer * Copyright (c) 2009 Alex Converse * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "aac_ac3_parser.h"#include "adts_header.h"#include "adts_parser.h"#include "get_bits.h"#include "mpeg4audio.h" int ff_adts_header_parse(GetBitContext *gbc, AACADTSHeaderInfo *hdr){    int size, rdb, ch, sr;    int aot, crc_abs;     memset(hdr, 0, sizeof(*hdr));     if (get_bits(gbc, 12) != 0xfff)        return AAC_AC3_PARSE_ERROR_SYNC;     skip_bits1(gbc);             /* id */    skip_bits(gbc, 2);           /* layer */    crc_abs = get_bits1(gbc);    /* protection_absent */    aot     = get_bits(gbc, 2);  /* profile_objecttype */    sr      = get_bits(gbc, 4);  /* sample_frequency_index */    if (!ff_mpeg4audio_sample_rates[sr])        return AAC_AC3_PARSE_ERROR_SAMPLE_RATE;    skip_bits1(gbc);             /* private_bit */    ch = get_bits(gbc, 3);       /* channel_configuration */     skip_bits1(gbc);             /* original/copy */    skip_bits1(gbc);             /* home */     /* adts_variable_header */    skip_bits1(gbc);             /* copyright_identification_bit */    skip_bits1(gbc);             /* copyright_identification_start */    size = get_bits(gbc, 13);    /* aac_frame_length */    if (size < AV_AAC_ADTS_HEADER_SIZE)        return AAC_AC3_PARSE_ERROR_FRAME_SIZE;     skip_bits(gbc, 11);          /* adts_buffer_fullness */    rdb = get_bits(gbc, 2);      /* number_of_raw_data_blocks_in_frame */     hdr->object_type    = aot + 1;    hdr->chan_config    = ch;    hdr->crc_absent     = crc_abs;    hdr->num_aac_frames = rdb + 1;    hdr->sampling_index = sr;    hdr->sample_rate    = ff_mpeg4audio_sample_rates[sr];    hdr->samples        = (rdb + 1) * 1024;    hdr->bit_rate       = size * 8 * hdr->sample_rate / hdr->samples;    hdr->frame_length   = size;     return size;}